Alignment Specs For Modified Street Car

[metalvolks]

Hello,

I have an '87 325IS. I just put new BMPDesign (KAMAX) upper adjustable strut mounts, rear trailing arm adjustable bushings, H&R sport springs and Bilstein sports. I have 15X7 wheels.

What is the best specs for toe, castor, and camber for front and rear. It's my daily driver and want to make my Falken's last a little while, but I like to play around with it to (so not totaly stock!).

I was thinking minimal toe 0.05-0.1 and -1 to -1.5 degrees of neg. camber. Would this work? What about Castor?

I have a lifetime alignment contract with Firestone, but they don't know how to align my car 1) Has been lowered 2) Rear stock specs are not published.

Let me know your suggestions!

Paul

[Lazr111]

Hello,

2) Rear stock specs are not published.

I was told that the e30 is a front-only alignment by the shop I take mine to, and they do mostly race prepped cars,so they know their shit.

[whiltebeitel]

e30's, unless you have installed a rear toe/camber adjustment on the rear subframe and/or camber plates, can only adjust front toe. 1/32 toe out gives good treadwear and decent turn in.

[erik325i]

I was told that the e30 is a front-only alignment by the shop I take mine to, and they do mostly race prepped cars,so they know their shit.

Yeah, stock, only the front toe is adjustable, but when you have camber/caster plated in the front and eccentric trailing arm bushings in the rear, you can adjust much more.

I'd say to put your front toe to stock spec, and give yourself more negative front camber. -1 to -1.5 is not nearly enough. I run -2.2 and it's still not enough for me, although I do drive it hard.
Caster, i'd set to m3 spec.

Rear, put the toe to stock spec and I'd try to run -2 camber

-Erik

[fretburnr]

erik's got it. I prefer around -2* camber in the front, a bit more during autox season, and as much caster as allowed by the adjustment plates while still being even left to right. Should provide good straight-ahead feel and plenty of dynamic camber on turn-in.

[Madhatter]

you cant have it both ways im affraid, if you want to get the most out of your car and really want a good setup, it isnt going to lead to good tyre life. A big part of your setup will depend on just how good your tyres really are.

If you want to go for good handling

Front
as much front caster as you can dial in
more front camber, upwards of 3 degrees
around 2mm toe out

Rear
0 toe in, or at the most about 0.5mm
lower negative camber, around 0.5-0.75' (at most 1') returns good results.

If you want it for the street, adding a little camber can help but its not going to be a huge improvement, so dont go overboard as its not worth it (vs tyre wear you can encounter), adding more castor makes a big difference to turn in and its probably what you will notice best. Take some of the toe out of it (even to the point of running a bit of toe out), will make it feel more stable under load, help it turn in better and will increase grip, especially given the added castor.

Adding castor and having it toe in tends to make them feel a little darty and skittish, can be difficult to drive as small adjustments to the steering wheel can be touchy. Good straight line stability, but they dont turn in well.

Dont really need to run any toe on the rear, but again, lower camber actually helps them grip up, especially if you have a fair bit of power. Id probably leave it at stock.

[kendogg]

My alignment was done by the best alignment shop in Atlanta (America's Best, the guy does lots of Ferarri racecar alignments, and owns an E30 himself :)) I can only adjust toe in the front, but I can adjust everything in the rear as well. Here is the alignment he used on my car, setup for road courses.

FRONT

L R
-1.4 Camber -1.6
8* Castor 8*
.16* Toe .12*


REAR
L R
-2.6* Camber -2.4*
.13* Toe .20*

*Bah. Stupid auto editing on this forum. If you can't figure it out from what I'm able to type, let me know, I can scan and email my alignment shet to anybody.